Fuel delivery systems for various vehicular applications, such as, for example, fuel-injected engines used in various types of on-road and off-road vehicles, typically include one or more fuel rails having a plurality of fuel injectors and fuel injector cups associated therewith. Some of these applications utilize fuel having a high alcohol content. For example, engines for certain automobiles and light trucks may operate on 100% ethanol fuel.
One downside of using this type of fuel is that in certain conditions (e.g., cold weather) the engine may be difficult to start due to the temperature of the fuel. One attempt at combating the “cold-fuel” problem involves heating the fuel before it is supplied to the fuel injector upon the starting of the engine.
For example, one known system includes a fuel rail having a plurality of outlets and a equal number of fuel injector cups associated with the outlets. When assembled, each fuel injector cup has a fuel injector disposed therein. Fuel from the fuel rail is communicated through the respective outlet to the fuel injector inlet disposed within the injector cup. To heat the fuel in this system, a separate component is affixed to the inner surface of the fuel rail proximate each outlet to create a heating chamber or volume for that particular outlet. A heating element is positioned within the chamber, and the component is configured to allow fuel from the flow channel of the fuel rail to flow into the chamber. Accordingly, the heating element heats the fuel in the chamber, and that fuel is then supplied to the fuel injector disposed within the injector cup corresponding to the respective outlet. Accordingly, a small volume of fuel is heated and supplied to the corresponding fuel injector to improve quick startability.
Such systems are not without their disadvantages, however. For example, in the system described above, the heating-chamber component is an additional component that must be added to the system. As such, the cost increases and the manufacturability of the system becomes more difficult. Additionally, the interface between the heating-chamber component and the inner surface of the fuel must be sealed to avoid the intrusion of cold fuel into the heating chamber. Again, this results in additional components being required, and accordingly, the cost and difficulty of manufacturability increases.
Therefore, there is a need for a fuel delivery system that will minimize and/or eliminate one or more of the above-identified deficiencies.